Linked from
The 6 pages that link to Glacial Lake Missoula, each with the reason it gives.
Glacial lakeBroader topic: Repeated drainage of the lake carved the Channeled Scablands.
Columbia River GorgeRelated: Its periodic drainage supplied the floods that scoured the gorge.
Proglacial lakeBroader topic: Its catastrophic drainage produced the Channeled Scablands.
Willamette RiverRelated: Its periodic release sent floodwaters westward toward the Willamette basin.